Feed-regulating apparatus for liquids



W. S. BOWEN FEED REGULA'IING APPARATUS FOR LIQUIDS July- 1, 1930.

Original Filed Dec. 24, 1926 YNVENTOR )VZ'ZZz'am Jpencerfiowen AT'TdRNEYReissued July 1, 1930 UNITED STATES PATENT OFFICE WILLIAM SPENCER BOWEN,OF WESTFIELD, NEW JERSEY, ASSIGNOR TO SMOOT ENGI- NEERING CORPORATION,OF NEW YORK, N. Y., A CORPORATION OF DELAWARE FEED-BEGULATING APPARATUSFOR LIQUIDS Original No. 1,651,992,

The invention relates to a system for controlling the supply of water orother liquid to a steam boiler or other evaporator in order that theproper quantity may be maintained therein; and it relates moreespecially to the high pressure type of boiler wherein greatfluctuations of the temperature of the water may occur. With the veryconsiderable differences in temperature which may prevail in boilers ofthis type, it will be apparent that the actual volume of the water ofthe boiler will swell or contract appreciably in accordance with thetemperature and load conditions. There is with the present apparatus ingeneral use, therefore, great difliculty in maintaining the properquantity of water in the boiler since the position of the water level inthe gauge glass does not afford a true index of the quantity, or rathermass, of the water therein. Moreover, the usual gauge glass for the feedwater is of necessity located at a position corresponding to the normallevel of the water in the boiler and is generally at a considerabledistance from the boiler floor level, making it diflicult' for theoperator to view the indication in the gauge glass.

The present invention has for its object a novel feed regulatingapparatus for maintaining the proper quantity of water or other liquidin the boiler or other evaporator for liquid and irrespective oftemperature and load conditions; also, to enable indicating apparatustherefor to be located at a suitable point so as to be convenient forobservation.

The nature of the invention, however, will best be understood whendescribed in connection with the accompanying drawing, which is a moreor less diagrammatic representation of the invention as embodied. forexample, in connection with a steam boiler.

Referring to the drawing, 1 designates the floor of a boiler room or thelike and by which is supported the boiler structure embodying thefurnace portion 2 and the boiler dated December 6, 1927, Serial No.156,830, filed December 24, 1926. Application for reissue filed November27, 1929. Serial No. 410,270.

tubes 3 and drum 4, as well as the headers 5 and 6 for the tubes. Thedrum 4 is supposed at all times to contain water, the normal level ofsame being indicated at 7; and heretofore it has been the practice tocontrol manually the supply of water to the boiler in observing thelevel of same in the drum through a suitable gauge glass or the like, asis well understood; or, automatically, by means of suitable floatcontrolled apparatus, the float rising and falling with the level of thewater in the drum of the boiler. Further expedients, such 'as steam andelectrically controlled apparatus, have been utilized for this purpose;but all depend in their operation on the actual level of the water inthe drum.

In accordance with the present invention, nothing of this nature isemployed; but the operation, while entirely automatic, is dependent noton the actual level of the water in the boiler but rather upon itsdensity at a predetermined temperature. That is to say, while the actuallevel of the water may vary within comparatively large limitstheminimum, of course, being always above the safe level-the operation ofthe feed mechanism for supplying the water to the boiler and at a pointsuch that it will always be i open to the steam space thereof. By thismeans, the boiler pressure will always remain equalized in the two legsof the U-tube member upon opposite sides of the mercury column 12thereof. thus balancing this column. The water of the boiler, however,will disturb this balance to an extent depending upon the hydraulic headthereof. .However, the height of this column, as will be\ understood, isa function of the temperature of the water, so that even though theactual height of the water column increases with increase oftemperature, and vice versa, this difference in height will have noeifect upon the position of the mercury column 12,

as the actual weight of the water acting thereon is not altered. Means,hereinafter described, are provided for controlling the supply of waterto the boiler through the variations in the height of the said mercurycolumn 12; and it will be understood that such means are to be soadjusted that they will not be actuated until the weight of theaforesaid column of water, irrespective of its actual height in theboiler, falls below a certain predetermined amount and which wouldcorrespond to an unsafe level of the water in the boiler at the coolesttemperature of said water employed therein.

Apparatus for affording the supply of water to the boiler may compriseany suitable well-known or special type of steam pump-control valve 15actuated as by an electro-magnetic member as a solenoid 16 of anywell-known or special design, said solenoid being in turn controlled byan electric current from a suitable source of supply as the battery 17.The said solenoid and battery are to be included in circuit with theU-tube member 11, one of the leads 18 being connected to the mercurycolumn 12 and the other extending into the top of the U-tube as at thesteam leg thereof and at a point normally in contact with the mercurycolumn 12 which corresponds to a safe quantity of water in the boiler.As the water in the boiler becomes depleted, it will be understood thatthe higher or steam leg of the mercury column 12 will gradually drop inthe U-tube in accordance with the reduced weight of the water in saidboiler and until it no longer makes contact with the one lead 18extending through the upper portion of said U-tube leg. Under theseconditions, the solenoid responds to actuate the pump-control valve forstarting up the pump 19 and by which feed water is supplied through theconnection' 20 to the boiler, the pump continuing to operate untilsuflicient mass of water has been delivered to the boiler-to again causethe mercury column 12 to ascend in the U- tube to a point where it makescontact with the exposed lead 18. This completes the circuit to thesolenoid, operating thereby the pump control valve in manner wellunderstood to shut ofi' the supply; and, if desired, a relay alarmdevice indicated at 21 may be, included in either of the leads 18 togive notice of the filling of the boiler..

Moreover, it will be noted that the U-tube is located substantially atthe lowermost part 7 of the boiler and therefore will be convenientlysituated for observation, so that the 7 actual conditions prevailing maybe observed also in the U-tube 11.

I claim:

1. The combination with evaporating apparatus, and means for supplyingliquid thereto; of a pressure-responsive device ex- -of; and meansoperated by the prevailing difference in pressure to which saidpressureresponsive device is exposed for controlling the supply of watertothe boiler.

.3. The combination with a steam boiler, and means for supplying waterthereto; of a mercury U-tube member, having one leg connected to theboiler substantially at its lowermost point and the other leg constantlyto the steam space of the boiler; an electromagnetic device, and asource of electricity connected to the mercury column of said U- tubemember; and means controlled by said electro-magnetic device under theinfluence of said mercury column for regulating the supply of water tothe boiler.

4. The combination with a steam boiler,

and means for supplying water thereto; of

connected to the mercury column, the latter normally closing the circuitto said electromagnetic device; and means controlled by saidelectro-magnetic device under the influence of the mercury of saidU-tube for regulating the supply of water to the boiler.

5. The combination with a water-tube boiler and means for supplyingliquid there to, of a regulator for said supplyin means, a deviceresponsive to the density of the liquid in the boiler and to the levelof the liquid therein, and means for controlling said regulator by saiddevice to maintain a predeter minrled relation between said density andsaid leve 6. The combination with evaporating apparatus, and means forsupplying liquid thereto, of regulating apparatus therefor including twochambers, a connection between one of said chambers and the lowermostpart of the evaporator, a connection between the other of said chambersand the vapor spa'ce of the evaporator whereby the difference inpressure between said chambers acts to control the supply of liquid.

7 The combination with a. steam boiler and means for supplying waterthereto, of a device responsive to the difierence in pressure betweenthe vaporspace of the boiler and the lowermost part of the boiler, andmeans controlled by said device tending to adjust the feed watersupplying means upon variation in said pressure diflerence.

' In testimony whereof; I have signed my name to this specification.

WILLIAM SPENCER BOWEN.

